Denise Nichols, the center's vice president, said alarmed vets from Alabama, Florida, Kansas, North Carolina, West Virginia and Wyoming have contacted the group about the mix up. Nichols said the VA is blaming the mistake on a coding error.

One vet, former Army Sgt. Samuel Hargrove, cried upon opening his letter.

"I can't even describe the intensity of my feelings," said the North Carolina father of two. "With so many health issues that I already have, I didn't know how to approach my family with the news."

In a statement Monday night, the VA said it's working to identify those who received the notification in error.

"We are trying to work with the VA because we realize it was an error and they were trying to do something right for the people who were diagnosed with ALS," Nichols said. "Basically this was a good effort that ended badly."